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Ohm Model L Midrange and Tweeter not Working

vqstaphbeard

vqstaphbeard

New Member
I acquired a pair of Ohm model L speakers from a thrift store. I did a re-foam of the woofers and upon initial testing discovered the tweeter and midrange drivers are not working in one of the speakers (the woofer does work).

I swapped the speakers between left and right channels to be sure it wasn't the amp, it wasn't. My initial thought was that it would be the crossover or internal wiring as both drivers were not working. I tested the midrange driver with a battery and nothing. I then turned the bass down on the amp and hooded the midrange driver right to the amp leads and slowly turned up the volume to be sure (I know some of you are cringing but I wanted to double check after the battery test) and no sound. I then took a test speaker and hooked up the internal wires that went to the midrange driver to the test speaker and hooked up the amp leads to the Ohm speaker in question. Played some music and the test speaker has sound. I did the same for the tweeter and same results.

I have now purchased replacement drivers. So my question now is what caused this and should I be concerned about the same happening to the replacement drivers? Could a bad crossover cause this and if so should I inspect it somehow? Anything else I should look for?

Thanks in advance for any replies.
 
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You want to know what caused your drivers to fail and if components in your xover could be the cause. Well, anything is possible. Have you looked at the xovers?

Do you see signs of over heating?

The major cause of high frequency driver failure is clipping in amps. That is pushing amplifiers too hard for prolonged periods of time. The clipped signal causes super high frequencies being sent to the high frequency drivers and ultimate failure. Now again, that is the major cause of failure. I don't think anyone can say for certain what caused the failure in your speakers.

Regards,
Jerry
 
Thank's Jerry.

I have looked at the crossovers and nothing looking glaringly obvious. I haven't taken a meter to anything as I don't have one; maybe this will give me an excuse. I suspected clipping but as it didn't happen under my watch I can't say for sure. Which is why I wanted to make sure it wasn't the crossover.
 
There are capacitors in between the input and the mid and tweeter drivers that should be checked. Possibly resistors too. If they seem to play OK you are probably fine but anytime things get fried, the damage may be more widespread than the component that actually failed.

Did you replace with the correct original drivers?
 
There in-lies my concern. I did get OEM replacement drivers, but I don't want to install them to find out the old ones fried because of something else and have the same happen to the new ones. The new drivers arrives today, so I'll be getting into this when I get home from work.
 
If you install the new drivers and play something at low volume, and turn the balance L to R and compare the sound, and the two speakers sound pretty much the same, that's a good indication things are not trashed in the crossover. Possible that one channel of the amp they were using clipped badly on a heavy bass note, or had defective components to begin with that the other channel didn't, and that's why drivers blew on one side but not the other. I would still be checking the components but if they sound OK they probably are OK at least at moderate volumes. You won't blow anything up with a careful test.
 
Will do.

I did a similar test by hooking the tweeter and midrange directly to an amp with the bass down and volume really low, so I'll try the same thing. Thanks!
 
Just finished installing and testing the new drivers. They sound great, so it must have been clipping. Thanks again to all that replied!
 
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